add github action for docs building

.github/workflows/build_docs.yml

@@ -0,0 +1,68 @@
+# Building and hosting documentation for PACKAGE_NAME
+#
+# Notes:
+#   - After the first run of this workflow:
+#       - Within the project repo, navigate to Setting/Github Pages
+#       - set `the source pbranch to `gh-pages/(root))`.
+#   - Uncomment evertything below the following line to enable the workflow.
+#---------------------------------------------------------------------------
+
+ name: Build Docs
+
+ on:
+   push:
+     # Sequence of patterns matched against refs/tags
+     tags:
+       - 'v*' # Push events to matching v*, i.e. v1.0, v20.15.10
+   workflow_dispatch:
+     inputs:
+       version:
+         description: Manual Doc Build
+         default: test
+         required: false
+ jobs:
+   docs:
+     name: build & push docs
+     runs-on: ${{ matrix.os }}
+     timeout-minutes: 90
+     strategy:
+       matrix:
+         os: ['ubuntu-latest']
+         environment-file: [ci/311-BASE.yaml]
+         experimental: [false]
+     defaults:
+       run:
+         shell: bash -l {0}
+
+     steps:
+       - name: checkout repo
+         uses: actions/checkout@v3
+
+       - name: setup micromamba
+         uses: mamba-org/provision-with-micromamba@main
+         with:
+           environment-file: ${{ matrix.environment-file }}
+           micromamba-version: 'latest'
+
+       - name: make docs
+         run: cd docs; make html
+
+       - name: commit docs
+         run: |
+           git clone https://github.com/ammaraskar/sphinx-action-test.git --branch gh-pages --single-branch gh-pages
+           cp -r docs/_build/html/* gh-pages/
+           cd gh-pages
+           git config --local user.email "action@github.com"
+           git config --local user.name "GitHub Action"
+           git add .
+           git commit -m "Update documentation" -a || true
+           # The above command will fail if no changes were present,
+           # so we ignore the return code.
+
+       - name: push to gh-pages
+         uses: ad-m/github-push-action@master
+         with:
+            branch: gh-pages
+            directory: gh-pages
+            github_token: ${{ secrets.GITHUB_TOKEN }}
+            force: true